Backup now, or forever hold your peace - revised!
This is a condensed revision of the old backup tip.
A companion tip is my data recovery tip.
Apple has a great article on backing up as well.
Backing up is the most essential function you will do with any computer. It is not a question of
if you will lose data, but when. Upgrades, updates, new software installs, trashed files. power outages, natural disasters, and theft can all lead to situations where having a backup will save
your bacon. Viruses are not the only cause for concern. A backup is not truly a backup, unless it is in two distinct places separate from the original. Any backup can fail. Not knowing that you have another recourse if that fails when you have just wiped your machine, is asking for faith. So keep that in mind as you plan how to backup your Mac. Lastly, also check the software license of what you are backing up. Some may limit how you use the backup.
Backing up your data on a Mac consists of doing one of the following:
1. Saving your Home folder (users -> yourname folder)
2. Saving your CD/DVD installed applications. Apple's App Store and Adobe's Creative Cloud are both examples of internet based places to reinstall your applications. But keep in mind, if these are down, having a different backup can be handy. Also keep in mind the App Store generally only keeps the most current version of any application. If your machine is older, and not able to install the latest Mac OS, keeping a full installer and/or clone is probably wise, as you may not be able to retrieve the installer at a later time once the application is created for newer Mac OS versions. A clone usually manages to keep most licensing registration information intact, but be sure to follow the license agreement regarding this backups when doing so. Any questions should be submitted to the developer regarding how the license is maintained. Also the App Store may drop an application when the developer is no longer able to keep up with Apple's terms or disappears. Ask on this forum if you run into such vaporware if any alternatives are known.
3. Making sure your operating system is easy to
recover
4. Or a combination of all 3.
For Macs released July 20, 2011 and later Apple offers an internet recovery option
For Macs released between March 15, 2010, and July 20, 2011, a prebundled CD or USB stick included the operating system, though a clone of the machine is also usable. Some of
these also supported internet recovery if a firmware was installed.
For Macs released between January 7, 2006 and March 14, 2010, Snow Leopard retail 10.6.3 is available. It looks like this, and does not say Upgrade, dropin, or OEM on it:
Prior Macs all ran 10.5.8 or earlier. But having the original discs or a clone
backup is the best method of ensuring you can recover the Mac.
Clone backups do exactly what they suggest. They make an exact replica of your Mac at
the time of the clone. Run these when you aren’t doing anything else on your
Mac and all applications that save documents are closed. Additionally, clones
when successful can boot the Mac directly. Third party examples of Cloning Software
include
Carbon Copy Cloner - Additional documentation on recovery from it is also available.
Apple’s own Disk Utility functions as a cloning software using the restore function of Disk Utility.
It is typically a lot slower than third party cloning software, but still does the job. Also unlike third party cloning software they can’t bring an existing backup up to date without wiping the destination software. Cloning software typically also can make exact replicas of whole folders solving the
issue #1 above faster. They preserve the file permissions.
Time Machine, Apple has had since Mac OS X 10.5 and is a combination archive and clone solution, with one major exception. The Time Machine backup can’t be booted directly from, and either Mac OS recovery or installer disc or Migration Assistant from an existing installation is necessary to recover the information from. As an archival solution, you need to be aware that once time machine backup fills up, intermediate archives are automatically deleted to make room for newer backups. You can temporarily stop Time Machine backups through system preferences and copy their folders to other drives to ensure the backups aren’t lost. Sadly cloning software is not able to copy these archives directly. And they must be copied to similarly formatted drives using the Finder. This means a Time Machine backup folder created on an HFS Extended Journalled drive can't be copied directly onto an APFS formatted partition with the Finder.
For some printing one’s documents, copying one’s documents
to a flash drive, or external hard drive, or burning a CD is all the backup they
will need But the most important aspect of any backup is knowing you have two separate functional replicas of your originals somewhere.
iCloud, Google Drive, Carbonite and Microsoft OneDrive all offer internet based backups to what’s known as the cloud. But like any backup they aren’t perfect. Always test the integrity of files on your Mac regularly to ensure your backup is good. As the internet connections are usually asynchronous, large backups to the cloud can be especially slow, and many operate automatically unless you tell them not to. Understand the each cloud backup medium frequently works on basis of synchronizing what's on your computer with an offsite system.
iCloud is very clear "On My Mac" or "iCloud" when it refers to folders in the sidebar of the Finder. When it is on iCloud, it might be on your Mac, it might be in a temporary folder at the root of the Mac, or, and if you made sure it was on a folder locally on your Mac that isn't backed up as frequently by iCloud you can be sure it is safely on your Mac. Don't let your Sync folder be your only copy of files. It is convenient when seeing the files on iPads and iPhones, and on PCs via web browsers, but it can be misleading that it is backed up until you see it on a local folder. Remember the rule it must be on at least two distinct, preferably three distinct places at all times.
Lastly, there is a bug that some have reported about making a bootable backup on Big Sur and later with Apple Silicon Macs. It appears ZD.net has isolated a procedure that prevents that bug from rearing its head. If this issue should happen to continue after using their solution, please let the community know you have contacted the author to look for resolution and refer the author to their page that you have tried their sequence. The author of this tip does not have an M1 Mac with which to try the suggestions.